@Heyward43 I played with lasergrbl for a while. It is much more limited than LB, but it is written specifically for grbl lasers (obviously, right?). You cannot draw in it. You can only run gcode. It worked well for me. - again within the limitations of my defective laser. Itās freeware.
1 Like
@gwilki Thanks for that info. I downloaded it and gave it a quick try. Seems ok. Iāll have to do some reading for all of the parameter settings. Iām not really interested in using it for drawing. Just gcode runs. I have Vcarve-pro for drawing. Does Lightburn have drawing capability? I may just stick with lasergrbl for a while since itās free.
@Heyward43 Yes, H, you can draw in LB. I didnāt look into it much, but it is certainly not up there with VCPro for CAD/CAM. If I ever get my laser woes solved, Iāll be playing with lasergrbl, too. We can compare notes.
@Heyward43 H. Clearly I was wrong about the limitations of lasergrbl. Look at this video
Itās not up there with VCPro, but it can do some drawing stuff.
Nice! That works for me. Iām not planning on anything fancy until I learn the ropes. Then we will see how it goes.
By the way was that your laser mount that was posted on the forum (or was it facebook) or did I get that from one of the other guys. I have the dxf but no instructions on bolt sizes etc. Do you have that info?
My laser arrived today. Three days ahead of the adjusted arrival date. Changed from Sep 13th to Aug 30th and delivered today. Iām glad. Now just have to wait for the safety glasses next week.
Yep. I downloaded that one last night. Havenāt had much time to play around with it yet. Iāll update you later. Itās kind of hard to see how they really work without the laser installed yet but Iāll get there.
Hereās a couple of pictures of what I received. Iām going to have to rely on you guys to help me set this up. I didnāt realize the control board heat sink had a fan on it too. Nice. Now need to cut out the mounting plate and on to testing.
@Heyward43 Other than colour, thatās pretty much what mine looks like, H.
Here is a .dxf of the mounting plate that I made for the laser:
laser_bracket.dxf (9.1 KB)
YMMV, of course in terms of the holes that match to the laser, but the ones that match to the Mill bracket will be good. My laser used 3mm screws and the Mill bracket uses 5mm screws. I had them left over from the Mill build - bonus. I finally ended up attaching a thin steel plate to the Mill bracket with the 2 @ 5mm screws and putting magnets in the laser bracket. (You know how I love magnets) Now I can just pop it on and off. (If only it worked. 
Oh, quit whining, Grant.)
Between Kris and Andy, you have all you need in terms of wiring. I extended the fan and laser wires leading from the driver board to the laser using some 18/4 wire that I had. I put a computer 4-pin molex connector on the laser module and one on the new, long wire, so that it is easy to disconnect the laser when Iām not using it. I ran it through the drag chains to keep everything pretty.
I expect, that like mine, yours did not come with the wire needed to run from the board to the LM controller. I scrounged a 2-pin connector from an old computer fan for the driver board end. The LM, of course, has its own 2-pin green connector. Watch polarity on this one. The way in which the fan plug mated with the driver board meant that the red wire was -, not +, as usual.
I mounted the driver board to a piece of wood so that it was vertical, keeping the fan free of any obstacles. It is mounted on a small shelf under my table.
As Kris advised, I got inline switches on Amazon that simply plug and play into the cable from the laser power supply to the driver board.
Here are mine:
Gxilee DC 12v Inline Toggle Rocker On Off Switch Kit for 3528 2835 5050 5630 LED Light Strip, CCTV Security Camera, Includes 3 x Black Manual Inline on Off Switch, 3 x Female 5.5 x 2.1mm DC Power Plug Adapter, 3 x Adhesive 3M Tape (2.1x5.5mm 12V Inline Switch)
Thatās about it. Kris was far more eloquent and comprehensive in his description and Andy did a video. This is my meagre input to the process.
Have fun.
2 Likes
Has anyone left laser mode on for milling?
The longmill has no spindle control, so does it really matter to turn it off?
The GRBL doc says:
WARNING: If you switch back from laser mode to a spindle for milling, you MUST disable laser mode by sending Grbl a $32=0 command. Milling operations require the spindle to get up to the right rpm to cut correctly and to be safe, helping to prevent a tool from breaking and flinging metal shards everywhere. With laser mode disabled, Grbl will briefly pause upon any spindle speed or state change to give the spindle a chance to get up to speed before continuing.
Since it seems to only impact stopping motion for spindle changes, I donāt expect it would do much.
Thoughts?
I found this - makes sense:
Laser Mode : The ālaserā mode will cause GRBL to move continuously through consecutive G1, G2, and G3 commands with spindle speed changes.
When ālaserā mode is disabled, GRBL will instead come to a stop to ensure a spindle comes up to speed properly.
Steve
@JayDent I left laser mode and the lower speed setting on by mistake and did not see any difference
in the performance of the router on my next job. I would not take this as gospel for all jobs, though.
1 Like
@chrismakesstuff - Do you have a thought on this? From all I can see leaving laser mode on will not change the behavior of the Longmill at all.
Leaving it in laser mode may only be an issue if you have a spindle instead of a router and are actually changing spindle speed during run. I think the idea in CNC mode is to pause motion to give the spindle time to reach the new speed. This isnāt something you want to happen when using a laser.
Hello Alan, I am trying to get this same laser to work and am wondering if I can pick your brain regarding wiring between the laser board and the Longmill. Initially I had wired it so that the neg on the laser board went to the ground at the PWM connector and the pos to the PWM as per othersā recommendations. This makes sense to me but when I do so and plug the power in, the laser goes full tilt and there is a noise coming from the board. When I swap the wires around and try it, it seems right as I am now able to click the physical button on the laser board and see what appears to be a low power beam which would I assume be for positioning. Despite being wired backwards, it seems like its doing what it is supposed to with the exception of āfiringā in either lasergrbl or Lightburn. So my question is, is it normal (and was this the case for you) for the laser to come on full blast and make a whining noise? The same thing it does when its not plugged in to the PWM at all. I have triple checked all wiring and settings and am concerned the laser board is defective. Thanks in advance for any advice you could offer Alan. Cheers!
My laser does not have a low power button on it. My laser has 3 terminals on it; Power, Ground, and PWM. In my case I have the main power positive and ground going to a 12V 5A DC power supply. I have the PWM terminal tied to the Longmill PWM positive output. I have the ground terminal on the laser also tied to the ground of the PWM output as well.
Essentially, the grounds are tied together.
@GertJan. Would it be possible for you to post a picture of the resistor you installed between the pwm and board? I am trying to figure out how to do this but I do not know much about electronic wiring.
Thanks
Not sure if you found a solution to your laser always burning or not. I read a post on this thread that mentioned putting a resistor between the PWM and GRD terminals on the longmill. Itās been found that the long mill puts out too high of voltage for some laser boards to āseeā the PWM signal. The resistor brings that voltage down.
One person used a 1k (1000 ohm) resistor. Another used 4.9k or so. Personally I used 4.7k and all seems well now.
Just stumbled onto this post and thought Iād try to help out. I used a 4.7k resistor I believe. This made everything work properly for me. I seem to have the exact same laser as the original poster.
